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From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-arm@nongnu.org, qemu-devel@nongnu.org
Subject: [PATCH 2/5] target/arm: Enable FEAT_CSV2_3 for -cpu max
Date: Thu, 18 Apr 2024 16:20:01 +0100	[thread overview]
Message-ID: <20240418152004.2106516-3-peter.maydell@linaro.org> (raw)
In-Reply-To: <20240418152004.2106516-1-peter.maydell@linaro.org>

FEAT_CSV2_3 adds a mechanism to identify if hardware cannot disclose
information about whether branch targets and branch history trained
in one hardware described context can control speculative execution
in a different hardware context.

There is no branch prediction in TCG, so we don't need to do anything
to be compliant with this.  Upadte the '-cpu max' ID registers to
advertise the feature.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 docs/system/arm/emulation.rst | 1 +
 target/arm/tcg/cpu64.c        | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/docs/system/arm/emulation.rst b/docs/system/arm/emulation.rst
index 9388c7dd553..958c69f3799 100644
--- a/docs/system/arm/emulation.rst
+++ b/docs/system/arm/emulation.rst
@@ -31,6 +31,7 @@ the following architecture extensions:
 - FEAT_CSV2_1p1 (Cache speculation variant 2, version 1.1)
 - FEAT_CSV2_1p2 (Cache speculation variant 2, version 1.2)
 - FEAT_CSV2_2 (Cache speculation variant 2, version 2)
+- FEAT_CSV2_3 (Cache speculation variant 2, version 3)
 - FEAT_CSV3 (Cache speculation variant 3)
 - FEAT_DGH (Data gathering hint)
 - FEAT_DIT (Data Independent Timing instructions)
diff --git a/target/arm/tcg/cpu64.c b/target/arm/tcg/cpu64.c
index 9f7a9f3d2cc..4445c5a212b 100644
--- a/target/arm/tcg/cpu64.c
+++ b/target/arm/tcg/cpu64.c
@@ -1159,7 +1159,7 @@ void aarch64_max_tcg_initfn(Object *obj)
     t = FIELD_DP64(t, ID_AA64PFR0, SVE, 1);
     t = FIELD_DP64(t, ID_AA64PFR0, SEL2, 1);      /* FEAT_SEL2 */
     t = FIELD_DP64(t, ID_AA64PFR0, DIT, 1);       /* FEAT_DIT */
-    t = FIELD_DP64(t, ID_AA64PFR0, CSV2, 2);      /* FEAT_CSV2_2 */
+    t = FIELD_DP64(t, ID_AA64PFR0, CSV2, 3);      /* FEAT_CSV2_3 */
     t = FIELD_DP64(t, ID_AA64PFR0, CSV3, 1);      /* FEAT_CSV3 */
     cpu->isar.id_aa64pfr0 = t;
 
@@ -1174,7 +1174,7 @@ void aarch64_max_tcg_initfn(Object *obj)
     t = FIELD_DP64(t, ID_AA64PFR1, MTE, 3);       /* FEAT_MTE3 */
     t = FIELD_DP64(t, ID_AA64PFR1, RAS_FRAC, 0);  /* FEAT_RASv1p1 + FEAT_DoubleFault */
     t = FIELD_DP64(t, ID_AA64PFR1, SME, 1);       /* FEAT_SME */
-    t = FIELD_DP64(t, ID_AA64PFR1, CSV2_FRAC, 0); /* FEAT_CSV2_2 */
+    t = FIELD_DP64(t, ID_AA64PFR1, CSV2_FRAC, 0); /* FEAT_CSV2_3 */
     cpu->isar.id_aa64pfr1 = t;
 
     t = cpu->isar.id_aa64mmfr0;
-- 
2.34.1



  parent reply	other threads:[~2024-04-18 15:22 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-18 15:19 [PATCH 0/5] target/arm: Update emulation.rst, add some easy features Peter Maydell
2024-04-18 15:20 ` [PATCH 1/5] docs/system/arm/emulation.rst: Add missing implemented features Peter Maydell
2024-04-19 17:37   ` Peter Maydell
2024-04-18 15:20 ` Peter Maydell [this message]
2024-04-18 16:11   ` [PATCH 2/5] target/arm: Enable FEAT_CSV2_3 for -cpu max Philippe Mathieu-Daudé
2024-04-18 15:20 ` [PATCH 3/5] target/arm: Enable FEAT_ETS2 " Peter Maydell
2024-04-18 15:20 ` [PATCH 4/5] target/arm: Implement ID_AA64MMFR3_EL1 Peter Maydell
2024-04-18 15:20 ` [PATCH 5/5] target/arm: Enable FEAT_Spec_FPACC for -cpu max Peter Maydell
2024-04-18 16:15   ` Philippe Mathieu-Daudé
2024-04-24 23:15 ` [PATCH 0/5] target/arm: Update emulation.rst, add some easy features Richard Henderson

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